酸处理对海泡石表面及其结构性质的影响

EFFECT OF HCl TREATMENT ON THE SURFACE CHARACTERISTIC OF SEPIOLITE

用盐酸对海泡石进行改性 ,考察了酸浓度、处理时间对海泡石脱镁率的关系 ,通过氮吸附法 ,X衍射、红外光谱和热重分析等对改性海泡石进行了表征 ,探讨了不同脱镁率对海泡石比表面、孔径分布和晶体结构等的影响。结果表明 ,海泡石比表面与脱镁率之间存在对应曲线关系 ,当脱镁率为 36 %时 ,比表面可达 554 4m2 /g。随着改性海泡石脱镁率的增加 ,海泡石的微孔逐渐向中孔至大孔扩展 ,且扩展过程是不均匀的 ,海泡石内骨架Mg -OH和结晶水逐渐失去 ,而骨架Si-OH基增加 ,晶体结构逐渐转变为硅氧四面体结构。

The natural sepiolite has been treated with hydrochloric acid.The effect of acid concentration on Removed Magnesium Ratio (RMR) of sepiolite was investigated.The sepcific surface area,the pore diameter distribution and the structure of the modified sepiolite were sdudied by means of XRD,IR,TG and nitrogen adsorption.The results showed that there is a correlation between the sepcific surface area and RMR of sepiolite.When it is 36%,the sepcific surface area reached 554.4 m 2/g.With increasing of RMR of sepiolite,the micropore is gradually expanded,and Mg-OH and crystal water are decreased,but Si-OH is increased in the modified sepiolite.When RMR is over 80%,the crystal structure of sepiolite is transformed into silicon-oxygen tetrahedron.